the other day i decided to make a poster for my room of a molecule of DNA and a protein (to be announced). the DNA is a sort of test to see how difficult it is before i go crazy trying to make a protein, which is much more difficult considering folding, etc.
when i draw these molecules i want it to be perfectly accurate; ie, i want to write in the bond lengths, bond angles and bond energies. needless to say, this is quite a challenge.
i've had a bit of success thus far but i am not sure of one factor, that is the bond angles in a phosphate. i figured that phosphorus was SP^3 hybridized. i figured also that the bond angle would be 109.5 degrees (like the angles in methane) if the covalent radii of the phosphorus with respect to each of the oxygen atoms were equal. of course, the doubly bonded oxygen is closer, so consequentially i believe the angle between the doubly bonded oxygen and the singly bonded oxygen is greater than 109.5 degrees. the covalent radius of phosphorus is 164nm when singly bonded to an oxygen atom and 145nm when doubly bonded to an oxygen atom. is there a directly proportional relationship between the difference in bond lengths and the bond angles in this case?